4.5" Orion SkyQuest

Object: Ruprecht 139
Obs. place: Mosaic Canyon, Death Valley, California, USA (285 meters / 935 feet)
Date: 26./27.8.2011
NE Lim.mag: 7.7m (zenith)
SQM-L: 21.70 (zenith)
Background sky: 9 (excellent)
Seeing: 8 (excellent)
Transparency: 7 (excellent)
Weather: +39.1 - 32.2°C, humidity <10%, a breath of wind from the north, thunderstorm in the SE.

Description: Fairly decent. Between the Lagoon and Trifid nebulae but more to the west. 15* within 12'. Small, scattered grouping of stars visible in the NW (see X).
Ruprecht 139 with 4.5" SkyQuest @ 76x